Dehydrating plant



L. E. POST AND D. A. RIEDY.

DEHYDRATING PLANT.

APPLICATION FILED JUNE 9, 1919.

6 SHEET HEET I.

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L. E. POST AND D. A. RIEDY.

DEHYDRATING PLANT.

APPLICATION FILED JUNE 9, 1919.

Patented Aug. 17, 1920.

6 SHEETS-SHEET 2.

INVENTORS [A/VOON f. osr y 00065 4. Phi-0 A TTOR NE YS L. E. POST AND D. A. RIEDY.

DEHYDRATING PLANT.

APPLICATION FILED JUNE 9,1919.

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L. E. POST AND D. A. RIEDY.

DEHYDRATING- PLANT.

APPLICATION FILED JUNE 9. 1919.

Patented Aug. 17, 1920.

6 SHEETS-SHEET 4-.

INVENTORS Zmvoozv A. Pos 7 y 0000514.

A TTORNE YS L. E. POST AND D. A. RIEDYK DEHYDRATING PLANT.

APPLICATION FILED JUNE 9, 19H?- Patented Aug. 17, 1920.

6 SHEETS-SHEET 5.

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A TTOR NE YS L. E. POST AND ,D. A. RIEDY.

DEHYDRATING PLANT. PPLICATION FILED JUNE 9, 1919.

Patented Aug. 17,1920.

6 SHEETSSHEET 6.

INVENTORS Zmvoo/v LC. r 057 BY 00065 ,4. Ray

ATTORNEYS UNITED STATES PATENT OFFICE.

LANDON E. POST AND DODGE A. RIEDY, OF SAN FRANCISCO, CALIFORNIA.

DEHYDRATING PLANT.

To all whom it may concern:

Be it known that we, LANDON E. Pos'r and Doncn A. RIEDY, citizens of the United States, and residents of the city and county of San Francisco, State of California, have made a new and useful Inventionto wit, Dehydrating Plants; and we do hereby declare the following to be a full, clear, con cise, and exact description of the same.

This invention relates to dehydrating apparatus.

One object of the invention is to provide means simulating the natural processes of evaporation which will greatly facilitate the operation andv means for augmenting the dehydrating value or efliciency of a given volume of air circulated about the product to be dehydrated.

Another object of the invention is to provide a dehydrator of such construction that the various component parts are of unit construction, extensible and adaptable to conditions varying with the different products to be treated. It is a well known fact that evaporation occurs at all temperatures, the rate of said evaporation varying according to the amount of moisture already present in the atmosphere.

The hotter the air the more water it will hold, though as long as the air does not contain all the moisture it will hold evaporation will take place at all temperatures.

In nature, when the temperature of air,

full, or nearly full, of water is suddenlylowered, the reverse water leaves the air rain.

The present invention takes cognizance of these natural laws and provides mechanical means for determining and controlling the action takes place and in the form of dew or temperature and humidity of air before it.

is introduced to the evaporator proper.

Other objects of the invention will appear as this description proceeds.

Our invention is embodied in one form in the accompanying drawings, but we do not wish to confine ourselves to the precise construction shown herein, but rather to have this description and the appended claims construed broadly and to avail ourselves of any modification that may properly fall within the scope of our invention.

Specification of Letters Patent.

Patented Aug. 17, 1920.

Application filed June 9, 1919. Serial No. 302,915.

In the accompanying drawings Figure 1 is a side elevation of a dehydrating plant, a portion of same being broken away and shown in longitudinal section for the purpose of more clearly showing the path of circulation of air through the dehydrating chambers while being treated or processed in accordance with our invention.

Fig. 2 is a plan view of Fig. 1.

Fig. 3 is an end view of same, looking the direction of the arrow on Fig. 1. Fig. 4 is a vertical. central section of a humidity extractor and .furnace on a scale larger than that of the preceding figures.

Fig. 5 is an end view of Fig. 4, a portion being shown in section on the line VV of Fig. 4

Fig. 6 is a front elevation of a furnace, a portion being shown in section on the line V I-VI of Fig. 4.

Fig. 7 is a plan view of Fig. 4.

Fig. 8 is a side elevation showing the detail construction of a hollow eliminator plate.

Fig. 9 is an end view of the same.

Fig. 10 is a section of Fig. 8 'on the line X X looking in the direction of the arrow.

Fig. 11 is an end elevation partly in section showing one of the dehydrating chambers. V

Fig. 12 is a half end elevation of a hu midity extractor shown in detail in Fig. 8.

Referring to the drawings, Figs. 1, 2 and 11, the numeral 1 indicates a foundation, supporting structural channel iron uprights 2, to which are secured the side walls 3 and 4, and end walls 6 and 7, here shown of corrugated sheet iron.

The walls are inclosed above by a gable roof 9 of corrugated iron extending over that portion of the structure intended for a kiln while a shed roof 11 incloses the furnace 12 and a supply fan 13, driven by a motor 14.

The furnace room and the kiln are separated by a cross partition 17.

' The roof 9 is supported by rafters 18 to which are secured hangers 19 depending obliquely therefrom to support a conveyer track 21 for a hanger 22, adapted to convey a depending rack or tray binder 23 for carrying tiers of trays 24 over a course or track indicated at 26' on Fig. 2 in and out of the kiln. The kiln is provided with doors 27 sheathed with sheet .metal and hin ed as shown at 28 and provided with late cs 29 and with test holes 31.

The doors 27 open over a loading platform 32 supported on stringers 33 supported by studs 34 without the kiln. The wall 7 relative humidity removed before it is introduced by the fan into the furnace.

This isaccomplished in the novel structure hereinafter -described wherein the water content of the inrushing current of air is thrown repeatedly against internally water-cooled deflectors, which at once reduce the temperature of the air and precipitate the humidity. The moisture gath ers onthe external surfaces of said water- 'cooled deflectors whence it is drawn by the combined action of capillary attraction and gravity to an overflow leading to a trap and thence to the water circulation system or to a suitable waste pipe.

lin the later steps of the treatment, a damper in the rear of the stack may be opened to admit atmospheric air direct to the humidity extractor.

After the incoming air leaves the humidity extractor, it is subjected to an additional treatment in the furnace where the combined action of external static pressure and the absorption from the interior of the combustion flues cause the air to enter the kiln in a state best adapted to speedilyabsorb any moisture present in the contents of the trays in the kiln chambers.

A dehydrator of this sort to be adaptable to the many varied trade uses, such as drying vegetables, fruit and fish, should be of such construction-that the circulation of air may be controlled during the step by step passage through various unit compart- .of the air adjusted to fit the ments and the velocity and moisture content conditions revealed by kiln chamber tests. It frequently happens that for various reasons it is desirable to alter the degree ofhuinidity of the air and the path of its circulation. For

instance, in the drying of fruit or vegetables, if dehydrated air be introduced at too high a temperature, case hardening or surface sealing will take place and thecellular'honeycomb structure of the vegetable matter willnot be reached bythe process resulting in an inferior article of commerce.

of the incoming air.

Gradual permeation of the cell structure is essential to the process. With our dehydrator, warm air may be circulated through a staggered succession of trays in the chambers and aftera suitable time by turning on water in the humidity extractor, the air may be dehydrated and given greater absorptive properties, as the process progresses.

In order to insure uniformity of treatment of-the contents of the kiln chambers, we provide means for reversing the 'air travel during the latter stage of the process.

Dampers may be operated to change the circulation through the kiln. It is obvious that the process of evaporation or drying of any commercial product may be controlled in this way at every step, and it is possible to follow a predetermined formula or schedule to produce uniform quality of product from the kilns;

As before mentioned, the incoming air strikes eliminator plates in the humidity extractor which extract a portion of the moisture from the air. These eliminator plates are best shown in Figs. 8, 9 and 10 and consist of stamped sheet metal members 37,

which are preferably so arranged that water admitted between the same cools the sheet metal enough to cause condensation These eliminator plates are arranged within the passage 38, which passage receives the incoming air from a dampered opening near the stack and takes the same to the fan 13. Mounted at the lower edge of the sheet metal members 37 is a trough 39, which trough catches all moisture of condensation and carries the same to a splash pan 35. The dry air now passes from-the lower part of the humidity extractor indicated at 38* to the fan 13 before .mentioned. This fan delivers the air from 38- downwardly, as shown at 40. At this point it divides and passes through alleys 43 at the sides of a combustion chamber 41. Horizontal alleys 42 connect the longitudinal alleys 43 and provide for a free circulation of air beneath the combustion chamber 41. In passing along the alleys 43, deflectors 44 are encountered I which cause the air to rise at different points, and thereby the same is evenly distributed over the tubes which will be hereinafter described.

Upon rising a short distance, bafiie plates 45 are encountered which force the air toward thecenter of the furnace and around all of the tubes 59. After leaving the furnace this heated air passes upwardly and into a longitudinal duct 46. There may be several of these longitudinal ducts deriving heated air from one furnace, the number depending entirely upon the capacity of said furnace.

For the purpose of simplicity, only one duct and one drying chamber will be described, it being understood that the remain ing chambers are merely a duplication of the one described.

Heated air is taken from the duct 46 through a valve or damper 47 and carried downwardly to the point 48 where it strikes a deflector 49 which causes it to follow the course of the arrows, striking deflector 50 which reverses the direction of travel until the deflector 51 is encountered when the course is again reversed.

It will be noted that the points of the deflectors on opposite sides contact with alter nate trays, the purpose of which-is obvious. These trays are also placed in the chamber so that when slid into the chamber they will be staggered from front to back. A certain amount of circulated air will follow the path of least resistance and flow through the screen bottoms of the trays. Another advantage is that, should one tray become clogged, air can pass around the end or side of the tray without interfering with the proper operation of the compartment.

Upon reaching the lower part of the chamber, the air is forced out of the opening 53 from which it passes to a central alley 54 which is in the rear of the kiln chambers, thence it passes to the atmosphere through the stack 55, or if desired an ex haust fan 52 may be located in the top of the central alley 54 which will be used if the humidity rate of the exhaust air is too high for natural circulation.

The opening 53 may be closed by a suitable damper or hinged door. The dampers 47 may be operated in any convenient manner. We also provide a damper near the fan 13, on the intake side, and one at the point where the hot air enters the center alley in the kiln. The purpose of these dampers is to insure control of the temperature or volume of air delivered.

At the points 64, We provide dampers which we use when it is desired to reverse the direction of air passing through the kilns. When these dampers are in the position shown in dotted lines, the air forced from'the furnace through the opening 65 into the central chamber The stack 55 is closed from the atmosphere by a suitable damper and consequently the heated air is forced through'the lower openings 53 in the kiln chambers, thence upwardly through the trays of fruit being dried, and out through the damper 47. thence to the atmosphere through the reverse draft stack 66.

\V e provide a combustion chamber 41 having the usual arch. Carried by this arch are header members 56 and 57, the headers 56 being at the rear of the furnace and spaced slightly apart to provide for a member 58, which member forms a damper at the rear end of the furnace. This memher 58 causes the gases from the combustion chamber 41 to follow the course shown by the arrows A. Between the header members 56 and 57 and carried thereby are tubes 59. These tubes are undipped cast iron, double hubbed soil pipe and are slightly porous.

Above the header 56, we provide a smoke header (it), which header has preferably three openings from which galvanized iron pipes (51 are carried to a stack header 62. This header is attached to the stack 63 and forms an outlet for the fumes from said combustion chamber to escape.

By forming these pipes 61 of galvanized iron, we abstract any remaining heat which may be in the gases about to pass up the stack.

In Figs. 1 and 2, we have shown a water tank 67 connected by a pipe. 68 to spray heads 69 and TO. The spray heads 69 are located in the passage 38 at the point of entrance of the air. The spray heads 70 are located beneath the valves 47 drating chamber. These spray heads atoniize water admitted to them, and this results in raising the humidity of the air when desired. A suitable radiator 71 is provided for the purpose of heating water for the tank 67, as hot water gives better results. If the water is heated in a closed tank, it escapes steam through the spray heads, and in this vaporized condition is more readily picked up by the incoming air than if sprayed in a cold state.

The usual fittings, such as expansion pipe and safety valve, are applied at suitable points within the system.

The operation of our device is as follows The fire is started in the combustion chamber 41, after the racks have been placed in the chambers with the commodity thereon. The fan 13 is started which draws air through the screen opening 19 between the deck above the dehydrating chambers and the roof where it is partially heated by solar action. It then passes spray heads 69. These spray heads are in action when the plant is first started, and consequently the air becomes saturated and passes through passage 38, through fan 13 and to both sides of the combustion chamber. Here it passes upwardly in contact with deflector plates 44 and is guided over the tubes and discharged into passages 46, thence through valves 47 and into the dehydrating chambers. Here it comes into contact with the various bailies and trays of drying commodities, which results in same taking a circuitous course.

On reaching the bottom chamber, the air is exhausted through openings 53 into the central alley. and is exhausted therefrom either through the stack 55 or through the of each dehy- Y lows:--

moisture within the air.

exhaust fan 52 and then stack 55, thence to the atmosphere.

After the plant has been in operation a short time, the jets 69 and 70, after they have been turned on, are turned off, and Warm air is then passed through the course just outlined.

.W hen the commodity to bedried has been partially dehydrated, water is admitted betweendeflector plates 37, which causes the condensing of a large per centage of the By this time, the furnace is sufliciently hot, and the little moisture then contained is absorbed through the porous tubes, as before mentioned, resulting in a very dry air being delivered to the kiln chambers. Having thus described our invention what we claim as new and desire to secure by Letters Patent oi the United States is as fol- 1. In a dehydrator, thecombination'of a series of chambers, trays mounted within said chambers, a common hot air supply, means for conducting said hot air to said chambers independently, trays mounted within said chambers one abovethe other,

means for controlling the travel of heated air within said chambers, an air outlet near the bottom of said chambers passing into a central chamber, and an outlet from said central chamber to the atmosphere.

2. In an apparatus of the character described, the combination of a series of chambers, trays slidably mounted Within said chambers, means adjacent said trays for causing a desired circulation of air within said chambers, a common hot air supply for said chambers, means for introducing a portion of said hot air into each chamber as desired, a central chamber to the rear of said chambers, an outlet beneath "said trays, said outlet opening into said central and means for diverting said heated air chamber,

.from said common source into said central chamber and exhaust the same through its former point of entrance,

3. In a dehydrating apparatus, the combination of aseries of closed chambers, a furnace, an inclosure above said chambers, an inlet andan outlet in the opposite ends of said inclosure, an exhaust pipe attached to said outlet, a fan attached to said pipe, said fan forcing airfrom said inclosure through said furnace and to said chambers.

4. In a dehydrating apparatus, the combination of a series of closed chambers, a furnace, an inclosure above said chambers, an inlet and an outlet'in the opposite ends of said inclosure, an exhaust duct attached to said outlet, internally water cooled eliminator'plates mounted within said duct, a fan adapted to withdraw air from said duct and force the same overhot tubes within said furnace, and means for conducting said air from said furnace in its processed state to said chambers.

5,111 a dehydrating apparatus, the combination of dehydrating chambers, a iurnace adapted to furnish heated air to said chambers, said furnace having a fire box, header members above said fire box, tubes carried by said headers, a damper so arranged that the gases from the combustion chamber will take a circuitous coursethrough said tubes, said tubes being formed of a porous material, passages beneath sald combustion chamber and along the side thereoi and having communication with said pipes b etween said headers and means for conductmg sald air to said dehydrating chambers.

In testimony whereof we have hereunto r ,2 n set our hands at San rrancisco, eal, this day of April, 1919.

LANDQN 'E. IPQST. DQDGE A. RIE Y. In presence of- J. HENRY. 

